


this light, this fire that devours

by saucerfulofsins



Category: Voltron: Legendary Defender
Genre: Alpha Shiro (Voltron), Alpha/Beta/Omega Dynamics, First Time, Knotting, M/M, Multiple Orgasms, Omega Keith (Voltron), Plot What Plot/Porn Without Plot
Language: English
Status: Completed
Published: 2019-09-21
Updated: 2019-09-21
Packaged: 2020-10-25 10:49:20
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,188
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20722979
Author URL: https://archiveofourown.org/users/saucerfulofsins/pseuds/saucerfulofsins
Summary: Keith goes into heat at an inopportune moment and Red gets to see a little more of her and Black's pilots than she bargained for.“What do you need?” Shiro asks.The question itself is nothing strange; as the leader of the troupe, he’s asked it a million times before and he doesn’t expect an answer out of the ordinary, even though considering the circumstances he maybe should have.“Yourdick,” Keith snaps, quick and harsh as a whip. “Obviously.”





	this light, this fire that devours

**Author's Note:**

> Many of my greatest thanks to [Abbey](https://archiveofourown.org/users/sepia_cigarettes/pseuds/sepia_cigarettes), who enables me to produce much of what I do publish and beta reads between screaming, and also to [Kika](https://archiveofourown.org/users/Kika988), who also beta read, did so brilliantly and somehow managed to keep most of her composure throughout. (I don't think I did).

“Can I get some help here, please?”

Keith’s voice comes staticky over the noise-filled comms and Shiro shoots upright in his seat, called to attention. They’re mid-fight, hurtling the lions towards the flock of Galra cruisers that are trying their damnedest to get to the Castleship and taking them out one by one so they can get to the larger base ship.

It’s a small faction, thank God, because Shiro might not get through this otherwise.

“What do you need?” he asks.

The question itself is nothing strange; as the leader of the troupe, he’s asked it a million times before and he doesn’t expect an answer out of the ordinary, even though considering the circumstances he maybe should have.

“Your _dick_,” Keith snaps, quick and harsh as a whip. “Obviously.” Shiro’s heart flips in his chest in the second it takes for Keith to compose himself; Red blasts another ship to smithereens in the meantime. “For _God_’s sake, give me some god-damn backup, please, I can barely fucking _think_.”

“Yeah,” Shiro manages to croak out, switching Black to auto-pilot so he can breathe and find his composure.

From the corner of his eyes, he sees Yellow crash headfirst into an enemy cruiser that explodes into a storm of sparks; she shakes off the debris as Hunk tries to catch up with Keith. Pidge chokes over the comms but at least she manages to avoid any run-ins with the enemy. Lance isn’t quite so lucky; he’s laughing hysterically, almost shrieking, and promptly gets hit by the guns of at least three different ships before he finally ducks out of the way, turning Blue up into a somersault and out of the line of fire.

Keith’s sharp response doesn’t come entirely unexpected. The scent of pre-heat clings to Shiro’s clothes, strong enough that it is obvious even to betas, and even before Keith’s comment Shiro barely managed to focus on the flurry of movement surrounding him. Black’s consciousness is his saving grace, poking at his mind to drag him back to attention. He remembers the way Keith’s arms wrapped around his waist before they left the Castle, his muscles working and the way he buried his nose in Shiro’s neck for just a moment. Like he _needed_ to scent Shiro to calm down before entering the fight—and in all likelihood, he did.

All Shiro wants to do now give up on the fight and move the hell over to Red. To fuck Keith silly with a piercing biological urge that pulls at all of his instincts, telling him to _go, go, go_. They haven’t discussed this but this side of nature cannot be repressed and every cell in his body is screaming for a chance to breed Keith, to bend him over and fuck him until they lock together, and to knot him until he has satisfied their needs and Keith goes limp and limber under him.

They’ve never done any of _that_ before.

Another deep breath. _Inner peace_, he tells himself. _Soon_.

Right now, he needs to take seven—six, five, now—enemy ships before he can properly assess the situation and see if they can make it back to the base, all ships down.

Somehow, he manages to get through it all alive, albeit by gritting his teeth and going cross-eyed forcing himself to focus, all with the awareness that Keith must be in a worse state right now. Shiro is distracted to the point that one moment he’s attacking a medium-size cruiser and the next he’s flying into empty space, the situation under control and creating space for him to breathe again.

Turning Black around, he sees that they’ve wiped out the swarm of cruisers. Hunk and Lance tag-team the main ship, which is already alight with flames before it erupts in a series of explosions.

Biology needs what it needs; Shiro can’t fight it anymore.

In fact, he can barely think anymore as he heads straight for Red. He needs not question where the lion is; he knows instinctively. Once there, he puts on his helmet and dives from Black’s mouth, finding his way onto Red and running through the narrow corridor that takes him from the cargo deck to the cockpit. There, he finds Keith buckled over in his seat.

He’s got his hand between his legs, pushing and squeezing; sweat streams down his neck and mats his hair to his face as he pants and looks up at Shiro with bleary eyes.

“Shit,” Shiro curses, throwing off his helmet and kneeling in front of Keith, grabbing his chin. He can smell him, sweet and heady, and he desperately wants to lean in to taste. Instead he tilts up Keith’s face so he can take a better look at him and asks, “Are you okay?”

Keith is still responsive, heaving out a dry “_yeah_”, although he’s evidently deep in the throes of his heat by now—and it’s a bad one, judging by the looks of it. Shiro knows that it has been a while, although Keith wasn’t clear on how long. It is entirely possible that it has been over a year; while Allura switched him to the next-best available alien surrogate, the suppressants he used back on Earth must have finally worn off. Pregnancy is certainly out of the question, but they’d hoped that with the new supplements Keith’s heat could be dodged entirely. Now, all the signs are present, blindingly obvious and not just in _Keith_.

_Fuck him_, his body screams. _Fuck fuck fuck him, fill him up_.

He shoves aside those thoughts, at least for now. Instead he grabs a bottle of water; Keith’s mouth must be dry, his body running too hot without relief. Shiro’s fingers tangle in the sweaty hair at the nape of Keith’s neck as he helps him drink. Meanwhile, Keith starts to shrug out of his armour; the motions send water spilling down the front of his undersuit.

A wet trail runs down Keith’s neck, water mixed with sweat, and this time Shiro can’t fight the urge to lean close. He licks it up, deeply inhaling Keith’s heat-scent as he goes, nudging his nose against the scent-glands under his chin and lingering for a moment.

He’s never been This Kind of Alpha, not even around Keith, but everything is different this time around. Maybe it’s because Keith hasn’t been in heat for a while; maybe because they’re so stressed or living in such close proximity, or maybe it is because Shiro has finally accepted that he _is_ in fact head over heels for Keith—and, in hindsight, has been for _years_. Hell, it could be a sheer matter of biology: they’re both without a mate and have always been more than compatible.

The air between them is thick with Keith’s scent when he finally reaches out and zips down the back of his black undersuit, asking, “You’re really okay with this, yeah?”

Keith nods, mutters, “Always, fuck, wanted this, always _you_—”

That’s enough for Shiro. Within seconds he has Keith naked and gets to see how hard he is, how _wet_—slick drips down his thighs from how badly he needs to get fucked, smearing around on the chair, filling the air with the scent of honeyed musk. Shiro wants to bury his nose in Keith’s ass, lap up the mess with his tongue, take in all that he can. “Need you in me,” Keith adds on a shivering gasp, “need you in me _now_, feels like I’ll die, _God_.”

When Shiro doesn’t immediately, he reaches down and shoves two fingers up his own ass, then three, whimpering like nothing is _enough_ right now—and Shiro knows that’s the truth.

He begins to claw at his own armour, tearing off the cuirass and gauntlets before he shoves down his undersuit. He lets the fabric cling to his legs as he hoists Keith from his seat and sits down in his place, feeling the wetness Keith left there under his own ass. Then he pulls his best friend into his lap; he takes a moment to grab his cock and drag it over Keith’s hot hole before allowing Keith to sink down onto him.

Shiro groans at the feeling of velvet hot tightness around his dick. Keith’s rim squeezes around him as he jerks his hips forwards once and comes, sighing deeply as he shivers and works himself through it, leaning forward to lick at the sweaty skin of Shiro’s neck. He nips at the sensitive skin with sharp incisors, the rolls of his hips slowly petering out.

If he hadn’t been about to enter a rut, Shiro would have come right now. But already his biology is changing to meet Keith’s physiological requirements; he needs something different right now, something _more_. He feels the tell-tale itch that informs him he’s getting ready to knot Keith, fucking him not just for pleasure but something else, something more, so he can pump Keith full of his come again and again.

“Fuck,” he whimpers desperately, dragging Keith’s face up with his fingers tangled into the sweaty black locks that he knows so well.

He kisses Keith like that, their first time and hard and deep and with too much tongue and teeth, spit smearing everywhere as Keith moans into his mouth and sucks on his lips. Shiro grabs Keith’s hips, plants his feet wide on the floor and begins to thrust his cock upwards into that tight, slick hole, ready and eager for Shiro to use.

“I feel so much better already,” Keith slurs, delirious, bracing himself on the back of the chair as he lets Shiro do what he wants. His hole sucks Shiro in, loose and wet, and Shiro can tell he’s ready to take his knot right now even though Shiro’s not quite there yet.

He does fuck up into Keith as good as he can—until he starts to slip, lose leverage, the angle too awkward to move fast and hard. He needs to be inside Keith deeper, as deep as he can, so he hauls Keith up and, keeping him planted on his dick, stumbles over to the control panel—because it’s got the almost-flat surface of a table, and because he can push Keith against it without Red responding, floating mid-space on her own accord so that Shiro can fuck Keith until his muscles tremble and his knees feel like jelly and Keith shouts, spilling between their abs, getting them even stickier than before.

Shiro begins to feel the tightening in his groin and he growls, slamming his palm down beside Keith’s head as he adjusts his angle. Keith squeezes around him, his hips rolling down to meet him, like his body needs _more_ of Shiro—and Shiro can give that to him. He _knows_ that he can, because he is a slave to his own nature.

He sets a punishing pace, his thighs burning as he fucks Keith as hard and deep as he can. Keith moans like he’s on the verge of coming again, but Shiro barely notices. His balls are tightening; he’s about to come, overwhelmed by the need to bury his cock inside Keith as deep as he can get before the knot at the base of his dick begins to swell.

Then he’s spilling, for the first time like this—Shiro hasn’t been with an omega before, much less an omega in heat and he thought he was prepared.

During previous ruts he has used fleshlights, pouring out the small pool of come afterwards before going at it again with the slap of his skin against soft plastic; he has used his hand to mimic the squeeze of a rim around his knot and letting everything wash down the drain, water cascading down on his back—but right now the squeeze of Keith’s rim milks him dry in a way he’s never experienced before.

_Nothing_ could have prepared him for this, he realises.

The first wave washes over him and immediately renders him helpless, his muscles pulsing and filling Keith with his come. He keeps his eyes closed and pushes his nose to Keith’s neck, wantonly moaning against the sweaty skin as his hips roll forward, closer, closer, closer.

Once he can breathe again, his dick still twitching feebly, he sees Keith has come again—he trembles around Shiro’s knot with his head thrown back and his knuckles white as he grips the edge of the control panel.

The sight is enough to send Shiro over the edge again, grinding his hips into Keith’s even though he can’t get any deeper, feels the tug of Keith’s tightness on his hypersensitive knot whenever he shifts a little, dragged right back into ecstasy. What follows is the most intense orgasm he’s ever experienced, helplessly bent over Keith’s lithe body and incapable of thought or action beyond the purely physical and immediate. He is shaking by the time it’s over, although the reprieve doesn’t last long—a third climax follows within a minute, although this time he manages to breathe through the pumping of his dick, burying his face back in Keith’s neck to steady himself and feeling tender fingers drag through his sweaty hair as he rides out the pleasure.

“_Oh_,” Keith whimpers, high pitched and weak. His hands are shaking as they come up to rest over Shiro’s arms and he lets his head thud back against the dimmed lights of the control panel, shifting on his back and spreading his legs a little wider. 

Shiro thinks he’s done when Keith shifts—and maybe he should have been. The aftershocks are almost painful although they consist of little more than a weak dribble of come pushing out, no comparison to the earlier abundance that leaks out of Keith regardless of Shiro’s knot still filling him up.

“I love you,” he mutters. Relaxation is finally settling into his gut, even if his knot won’t let up for another fifteen minutes or so—maybe longer—and they’ll have to move soon if they don’t want to end up with sore muscles from the awkward position. The meaning of his words only sinks in after thinking of the practicalities, but when he pulls back and looks at Keith, he doesn’t look shocked.

“Me too,” Keith responds, licking his lips and looking up at him. “Me too—just. Yeah. I love you too.”

When he squeezes around Shiro again, his dick manages another series of twitches, a dry orgasm that he grunts through even as he straightens his back. He realises this might happen another few times and ignores the aftershocks of pleasure so he can pull Keith upright and hitch him into the air—he’s not going to withhold his knot from Keith when he still needs it—and stumbles backwards to the piloting seat.

Once there, with Keith in his lap, they kiss again. He reaches down to slowly jerk Keith off, using the mess of his own come and Keith’s slick spread all over their legs to smooth out his strokes. He makes sure that his touch is teasing and slow; the worst of the heat has left Keith’s body for now but regardless he’s up for more, arching into Shiro’s touch and wringing out another dry orgasm. Shiro doesn’t speed up his touch until his knot has reduced enough that Keith can lift a little, still in his lap. Reaching down, he brushes two metal fingers over Keith’s rim, feels it puffy and dripping wet stretching around his sensitive and swollen knot.

He fucks Keith again like that, slow and deliberate and on the thick of his knot until Keith finally comes again, his dick spurting a few white streaks across Shiro’s chest.

He slumps forward and Shiro kisses him soft and deep, taking his time now that he can; they’re both filthy and this time Keith isn’t restless anymore, not eagerly grinding down onto Shiro’s softening dick inside of him.

Finally, he gently lifts Keith off his now too-sensitive cock and hauls him into Red’s tiny bathroom. There, he sits Keith down on the toilet and cleans him up with a wet towel. Come and slick continue to drip from his hole, and after wiping the mix away a few times, Shiro gives up on getting him fully clean. He knows that, more than anything, Keith needs to rest before another wave of heat inevitably hits him. He carries Keith to the small bed squeezed in opposite the bathroom and lies him down there.

Keith looks at him with sated and unfocused eyes, his legs spread, and Shiro takes a moment to stroke his hands over the vast expanses of skin—now all belonging to him; he knows he will stake a proper biological claim on Keith before the coming days are over. His fingers dip lower, curl around Keith’s dick and tug at it a couple of times, mostly perfunctory. Keith’s cock twitches but he doesn’t harden more and, satisfied that Keith truly _is_ okay right now, Shiro dips his fingers down further. He slides two into Keith’s hole, pushing some of the come that was leaking out back inside and keeping it there while Keith closes his eyes and heaves out a deep sigh, lazily scratching at his stomach.

“Try to sleep for a while,” Shiro suggests, brushing his free hand over Keith’s forehead.

Keith nods, shifts, licks his lips. “Can you keep your fingers in me?”

Shiro huffs out a laugh. “Yeah. You like that? Me filling you up like that?”

Keith doesn’t open his eyes even as he curls up against Shiro’s body, like he needs more contact than just two fingers slowly fucking him. Shiro accommodates him, lets Keith take hold of his free hand and press it to his cheek. “Yeah,” he says. “Makes me feel full, like I’m not alone—it keeps away the heat better, I think.”

Shiro snorts. “I think that’s just my come inside of you.”

Keith hums but doesn’t bother to formulate a proper response, already drifting off to sleep—and Shiro understands. He knows Keith’s struggled to pay attention all throughout the fight, the heat burning up his energy like crazy. After that and then Shiro fucking him, he isn’t surprised that Keith is exhausted.

They should probably get back to the Castle for food and a bath, but there’s something about the privacy of the Lion that he prefers. He thinks it might be partially Red’s instinct, tapping into him to say that this is the safest place for Keith to be right now.

He decides to let Keith sleep here and sends a message down to the Castle to tell the other Paladins not to worry, that they’ve got everything covered, and will probably make it to the Castle in another few hours.

Keith snores lightly, shifts a little and grinds his ass back on Shiro’s fingers. He keeps them there and strokes the hair from his face, his thumb down the sharp line of Keith’s jaw, and waits patiently until he wakes up and needs Shiro to fuck him again.

**Author's Note:**

> Title taken from a poem by Federico Garcia Lorca, translated to English by Walsh and Aragon in _Love Speaks Its Name: Gay and Lesbian Love Poems_, p. 162.
> 
> Comments of all kind are appreciated :)


End file.
